This is a term used by women to describe men that they find unappealing or unattractive, but are too nice to say it outright. It is most commonly used when they are explaining to one of these unappealing men that they do not want to go out with them.

"Would you like to go out with me Agnes?"
"Uh, well, you're sweet, but I don't really see you that way Steve"

In street lingo this means a push over or a weak individual. It is equal to calling someone gay, a fruit, a fairy, a queer, a queen, a homo, a baby, a whinner... generally very bad. When heard in rap (hip hop) it is ment to be in insult.

Not to be confused with the non-street version of the same word (which is the good version aka the suburban kid version).

A title reflecting a person's high economic, social and 'street business' status, brought into common culture by pimps in the 1970s, yet brought back into wide circulation by Pimp C when he adopted the alter-ego of Sweet James Jones.
As a title, Sweet is analogous to Sir for English people, and other similar titles commanding respect.
Sweet can also refer to a gorgeous honey (girl) who stands out among other girls.

Sweet James Jones was an innovator in the rap game and set forward the distinction between other rappers and hiphop music, and his Country Rap Tunes.